Variable capacitance chamber component incorporating ferroelectric materials and methods of manufacturing and using thereof

ABSTRACT

A replaceable chamber element for use in a plasma processing system, such as a plasma etching system, is described. The replaceable chamber element includes a chamber component configured to be exposed to plasma in a plasma processing system, wherein the chamber component is fabricated of a ferroelectric material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to co-pending U.S. patent application Ser.No. 13/366,340, entitled “VARIABLE CAPACITANCE CHAMBER COMPONENTINCORPORATING A SEMICONDUCTOR JUNCTION AND METHODS OF MANUFACTURING ANDUSING THEREOF”, filed on even date herewith. The entire content of thisapplication is herein incorporated by reference in its entirety.

FIELD OF INVENTION

The invention relates to a replaceable chamber element for use in aplasma processing system, and methods for manufacturing the replaceablechamber element and performing a plasma-assisted process using thereplaceable chamber element.

BACKGROUND OF THE INVENTION

The fabrication of integrated circuits (IC) in the semiconductorindustry typically employs plasma to create and assist surface chemistrywithin a vacuum processing system necessary to remove material from anddeposit material on a substrate. In general, plasma is formed within theprocessing system under vacuum conditions by heating electrons toenergies sufficient to sustain ionizing collisions with a suppliedprocess gas. Moreover, the heated electrons can have energy sufficientto sustain dissociative collisions and, therefore, a specific set ofgases under predetermined conditions (e.g., chamber pressure, gas flowrate, etc.) are chosen to produce a population of charged species andchemically reactive species suitable to the particular process beingperformed within the system (e.g., etching processes where materials areremoved from the substrate or deposition processes where materials areadded to the substrate).

Although the formation of a population of charged species (ions, etc.)and chemically reactive species is necessary for performing the functionof the plasma processing system (i.e., material etch, materialdeposition, etc.) at the substrate surface, other chamber componentsurfaces on the interior of the plasma processing chamber are exposed tothe physically and chemically active plasma and, in time, can erode. Theerosion of exposed chamber components in the plasma processing systemcan lead to a gradual degradation of the plasma processing performanceand ultimately to complete failure of the system.

As an example, during plasma etching for semiconductor devicefabrication, the termination of the peripheral edge of the substrate isimportant and, when not addressed properly, can change plasma propertiesand affect etching uniformity. A chamber component, known as a focusring, is located beyond the peripheral edge of the substrate and,dependent on the material composition of the focus ring, it may spreador confine plasma above the substrate to improve etching performance,such as etching uniformity, especially at the peripheral edge of thesubstrate. However, the focus ring is consumed during plasma etching,which in turn degrades etching uniformity. And, as a consequence, thefocus ring must be replaced about every 200-400 hours the plasmaprocessing system is in operation.

As another example, during plasma etching for semiconductor devicefabrication, chamber matching is also a critical concern. Theconsumption of chamber components (e.g., focus ring, cover ring,electrode plate, etc.), the deposition of polymer on chamber components(e.g., deposition shield, etc.), and chamber capacity change thecapacitance of plasma processing chamber, which results in variableplasma properties as well as variable etching uniformity.

SUMMARY OF THE INVENTION

Embodiments of the invention relate to a replaceable chamber element foruse in a plasma processing system, and methods for manufacturing thereplaceable chamber element and performing a plasma-assisted processusing the replaceable chamber element. Embodiments of the inventionfurther relate to a replaceable chamber element having a variablecapacitance.

According to one embodiment, a replaceable chamber element for use in aplasma processing system, such as a plasma etching system, and a methodof manufacturing are described. The replaceable chamber element includesa chamber component configured to be exposed to plasma in a plasmaprocessing system, wherein the chamber component is fabricated of aferroelectric material.

According to another embodiment, a method for performing aplasma-assisted process is described. The method includes disposing achamber component in a plasma process system, wherein the chambercomponent is composed of a ferroelectric material. The method furtherincludes forming plasma for performing a plasma-assisted process in saidplasma processing system.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A through 1C provide schematic illustrations of a plasmaprocessing system according to several embodiments;

FIG. 2 provides an illustration of a method of varying the capacitanceof a replaceable chamber element according to an embodiment;

FIG. 3 illustrates the dependence of dielectric constant on voltageapplied across a ferroelectric material;

FIG. 4 provides an illustration of a focus ring and a method offabricating according to an embodiment;

FIGS. 5A and 5B provide a top view of a focus ring and an explodedcross-sectional view of an implementation of a variable capacitancefocus ring in a plasma processing system according to an embodiment;

FIG. 6 provides an illustration of an electrode plate and a method offabricating according to various embodiments;

FIG. 7 provides an illustration of a deposition shield and a method offabricating according to an embodiment;

FIG. 8 provides a flow chart illustrating a method of manufacturing areplaceable chamber element according to another embodiment; and

FIG. 9 provides a flow chart illustrating a method of performing aplasma-assisted process according to yet another embodiment.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

A replaceable chamber element for use in a plasma processing system isdisclosed in various embodiments. However, one skilled in the relevantart will recognize that the various embodiments may be practiced withoutone or more of the specific details, or with other replacement and/oradditional methods, materials, or components. In other instances,well-known structures, materials, or operations are not shown ordescribed in detail to avoid obscuring aspects of various embodiments ofthe invention.

Similarly, for purposes of explanation, specific numbers, materials, andconfigurations are set forth in order to provide a thoroughunderstanding of the invention. Nevertheless, the invention may bepracticed without specific details. Furthermore, it is understood thatthe various embodiments shown in the figures are illustrativerepresentations and are not necessarily drawn to scale.

Reference throughout this specification to “one embodiment” or “anembodiment” or variation thereof means that a particular feature,structure, material, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention, butdo not denote that they are present in every embodiment. Thus, theappearances of the phrases such as “in one embodiment” or “in anembodiment” in various places throughout this specification are notnecessarily referring to the same embodiment of the invention.Furthermore, the particular features, structures, materials, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Nonetheless, it should be appreciated that, contained within thedescription are features which, notwithstanding the inventive nature ofthe general concepts being explained, are also of an inventive nature.

“Substrate” as used herein generically refers to the object beingprocessed in accordance with embodiments of the invention. The substratemay include any material portion or structure of a device, particularlya semiconductor or other electronics device, and may, for example, be abase substrate structure, such as a semiconductor wafer or a layer on oroverlying a base substrate structure such as a thin film. Thus,substrate is not intended to be limited to any particular basestructure, underlying layer or overlying layer, patterned orunpatterned, but rather, is contemplated to include any such layer orbase structure, and any combination of layers and/or base structures.The description below may reference particular types of substrates, butthis is for illustrative purposes only and not limitation.

As described above, plasma processing systems and, in particular, plasmaetching systems, contain one or more replaceable chamber elementsexposed to plasma that require periodic replacement or refurbishment dueto plasma erosion and consumption. For example, the one or morereplaceable chamber elements may include a focus ring, a shield ring, adeposition shield (or chamber liner), a baffle plate, a bellows shield,an electrode plate, or an antenna window. According to variousembodiments, a replaceable chamber element having a variable capacitanceis described that, among other things, may be utilized to adjust one ormore plasma properties, such as plasma density, to achieve any one ofthe following: (i) alter plasma uniformity and etching uniformity; (ii)improve plasma processing chamber matching; (iii) reduce the seasoningtime following the cleaning of the plasma processing chamber; (iv)increase lifetime of the replaceable chamber element by compensating forplasma erosion and consumption; and (v) improve substrate-to-substrateand lot-to-lot matching.

Therefore, according to an embodiment, a plasma processing system 100Aconfigured to perform a plasma-assisted process on a substrate 135 isdepicted in FIG. 1A. The plasma processing system 100A comprises aplasma processing chamber 110, an upper assembly 120A, an electrodeplate/antenna assembly 124A, a substrate holder 130 for supportingsubstrate 135, a pumping duct 140 coupled to a vacuum pump (not shown)for providing a reduced pressure atmosphere in plasma processing chamber110, and one or more replaceable chamber elements (160, 162, 164, 126A,154, 114) having a variable capacitance.

Plasma processing chamber 110 can facilitate the formation of plasma ina process space 112 adjacent substrate 135. Plasma can be utilized tocreate materials specific to a pre-determined materials process, and/orto aid the removal of material from the exposed surfaces of substrate135. The plasma processing system 100A may be configured to processsubstrates of any size, such as 200 mm substrates, 300 mm substrates,450 mm substrates, or larger. For example, the plasma processing system100A may comprise a plasma etching system.

In the illustrated embodiment of FIG. 1A, upper assembly 120A mayprovide a grounded electrode opposite substrate 135. The upper assembly120A comprises electrode plate/antenna assembly 124A that includes anelectrode plate 126A and an electrode 128A. Electrode 128A may beelectrically coupled to ground, as shown, and electrode plate 126A maybe composed of a material compatible with plasma in process space 112.Due to the erosive nature of plasma, electrode plate 126A may beconsumed and may require periodic replacement or refurbishment. Forexample, electrode plate 126A may be a replaceable element composed of aferroelectric material, such as a material having a chemical formulaexpressed as A_(x)(B_(y)C_(1-y))O_(z), where A, B, C are metals and x,y, and z are positive real numbers. The ferroelectric material mayinclude barium titanate (BaTiO₃) or lead zirconate titante (PZT).Additionally, the ferroelectric material may be arranged between twoelectrodes. Furthermore, the electrode plate 126A may include aprotective layer formed on an exterior surface arranged to be exposed toplasma. The electrode plate 126A may be removably fastened to electrode128A.

Alternatively, in the illustrated embodiment of FIG. 1B, an upperassembly 120B of a plasma processing system 100B is shown. Upperassembly 120B may provide a powered RF electrode opposite substrate 135for plasma production. The upper assembly 120B comprises an electrodeplate/antenna assembly 124B that includes an electrode plate 126B and anelectrode 128B. Electrode 128B may be electrically coupled to a sourceof radio frequency (RF) energy, such as an RF generator, as shown, andelectrode plate 126B may be composed of a material compatible withplasma in process space 112. Due to the erosive nature of plasma,electrode plate 126B may be consumed and may require periodicreplacement or refurbishment. For example, electrode plate 126B may be areplaceable element composed of a ferroelectric material, such as amaterial having a chemical formula expressed asA_(x)(B_(y)C_(1-y))O_(z), where A, B, C are metals and x, y, and z arepositive real numbers. The ferroelectric material may include bariumtitanate (BaTiO₃) or lead zirconate titante (PZT). Additionally, theferroelectric material may be arranged between two electrodes.Furthermore, the electrode plate 126B may include a protective layerformed on an exterior surface arranged to be exposed to plasma. Theelectrode plate 126B may be removably fastened to electrode 128B.

As shown in FIGS. 1A and 1B, the plasma processing system (100A, 100B)may be configured as a capacitively coupled plasma (CCP) system.Alternatively, the plasma processing system (100A, 100B) may beconfigured as an inductively coupled plasma (ICP) system.

Alternatively yet, in the illustrated embodiment of FIG. 1C, an upperassembly 120C of a plasma processing system 100C is shown. Upperassembly 120C may provide a powered microwave antenna opposite substrate135 for plasma production. The upper assembly 120C comprises anelectrode plate/antenna assembly 124C that includes an antenna window126C and an antenna 128C. Antenna 128C may be electrically coupled to asource of radio frequency (RF) energy, such as a microwave generator, asshown, and antenna window 126C may be composed of a material compatiblewith plasma in process space 112. Due to the erosive nature of plasma,antenna window 126C may be consumed and may require periodic replacementor refurbishment. For example, antenna window 126C may be a replaceableelement composed of a ferroelectric material, such as a material havinga chemical formula expressed as A_(x)(B_(y)C_(1-y))O_(z), where A, B, Care metals and x, y, and z are positive real numbers. The ferroelectricmaterial may include barium titanate (BaTiO₃) or lead zirconate titante(PZT). Additionally, the ferroelectric material may be arranged betweentwo electrodes. Furthermore, the antenna window 126C may include aprotective layer formed on an exterior surface arranged to be exposed toplasma. The antenna window 126C may be removably fastened to antenna128C.

As shown in FIG. 1C, the plasma processing system 100C may be configuredas a surface wave plasma (SWP) system. Upper assembly 120C may include aslotted plane antenna (SPA), such as a radial line slot antenna (RLSA).

Although not shown in FIGS. 1A through 1C, a direct current (DC) powersupply may be coupled to the upper assembly (120A, 120B, 120C) opposingsubstrate 135. The DC power supply may include a variable DC powersupply. Additionally, the DC power supply may include a bipolar DC powersupply. The DC power supply may further include a system configured toperform at least one of monitoring, adjusting, or controlling thepolarity, current, voltage, or on/off state of the DC power supply. Onceplasma is formed, the DC power supply may facilitate the formation of anelectron beam. An electrical filter (not shown) may be utilized tode-couple RF power from the DC power supply.

For example, the DC voltage applied to upper assembly (120A, 120B, 120C)by the DC power supply may range from approximately −2000 volts (V) toapproximately 1000 V. Desirably, the absolute value of the DC voltagehas a value equal to or greater than approximately 100 V, and moredesirably, the absolute value of the DC voltage has a value equal to orgreater than approximately 500 V. Additionally, it is desirable that theDC voltage has a negative polarity. Furthermore, it is desirable thatthe DC voltage is a negative voltage having an absolute value greaterthan the self-bias voltage generated on a surface of the upper assembly(120A, 120B, 120C).

Referring to FIGS. 1A through 1C, the plasma processing chamber 110 mayinclude a chamber liner or deposition shield 114 configured to becoupled to at least a portion of an interior surface of the plasmaprocessing chamber 110. Due to the erosive nature of plasma, depositionshield 114 may be consumed and may require periodic replacement orrefurbishment. The inventors suspect that the deposition of polymer onthe deposition shield 114 during etching will have less influence on theetching uniformity and chamber matching when capacitance adjustment isutilized. As a result, the frequency for system maintenance, includingwet clean, will be decreased. For example, deposition shield 114 may bea replaceable element composed of a ferroelectric material, such as amaterial having a chemical formula expressed asA_(x)(B_(y)C_(1-y))O_(z), where A, B, C are metals and x, y, and z arepositive real numbers. The ferroelectric material may include bariumtitanate (BaTiO₃) or lead zirconate titante (PZT). Additionally, theferroelectric material may be arranged between two electrodes.Furthermore, the deposition shield 114 may include a protective layerformed on an exterior surface arranged to be exposed to plasma. Thedeposition shield 114 may be removably fastened to plasma processingchamber 110.

Referring to FIGS. 1A through 1C, substrate holder 130 further comprisesa focus ring 160, and may optionally comprise a shield ring 162 and abellows shield 154. Due to the erosive nature of plasma, focus ring 160may be consumed and may require periodic replacement or refurbishment.For example, focus ring 160 may be a replaceable element composed of aferroelectric material, such as a material having a chemical formulaexpressed as A_(x)(B_(y)C_(1-y))O_(z), where A, B, C are metals and x,y, and z are positive real numbers. The ferroelectric material mayinclude barium titanate (BaTiO₃) or lead zirconate titante (PZT).Additionally, the ferroelectric material may be arranged between twoelectrodes. Furthermore, the focus ring 160 may include a protectivelayer formed on an exterior surface arranged to be exposed to plasma.The focus ring 160 may be removably fastened to substrate holder 130.

Additionally, substrate 135 can be affixed to the substrate holder 130via a clamping system (not shown), such as a mechanical clamping systemor an electrical clamping system (e.g., an electrostatic clampingsystem). Furthermore, substrate holder 130 can include a heating system(not shown) or a cooling system (not shown) that is configured to adjustand/or control the temperature of substrate holder 130 and substrate135. The heating system or cooling system may comprise a re-circulatingflow of heat transfer fluid that receives heat from substrate holder 130and transfers heat to a heat exchanger system (not shown) when cooling,or transfers heat from the heat exchanger system to substrate holder 130when heating. In other embodiments, heating/cooling elements, such asresistive heating elements, or thermo-electric heaters/coolers can beincluded in the substrate holder 130, as well as the chamber wall of theplasma processing chamber 110 and any other component within the plasmaprocessing system (100A, 100B, 100C).

Furthermore, a heat transfer gas can be delivered to the backside ofsubstrate 135 via a backside gas supply system in order to improve thegas-gap thermal conductance between substrate 135 and substrate holder130. Such a system can be utilized when temperature control of thesubstrate is required at elevated or reduced temperatures. For example,the backside gas supply system can comprise a two-zone gas distributionsystem, wherein the helium gas-gap pressure can be independently variedbetween the center and the edge of substrate 135.

In the embodiments shown in FIGS. 1A through 1C, substrate holder 130can comprise a substrate holder electrode (not shown) through which RFpower is optionally coupled to the processing plasma in process space112. For example, substrate holder 130 can be electrically biased at aRF voltage via the transmission of RF power from a RF generator (notshown) through an optional impedance match network to substrate holder130. The RF electrical bias can serve to heat electrons to form andmaintain plasma. In this configuration, the system can operate as areactive ion etch (RIE) reactor, wherein the chamber and an upper gasinjection electrode serve as ground surfaces. A typical frequency forthe RF bias can range from about 0.1 MHz to about 100 MHz. RF systemsfor plasma processing are well known to those skilled in the art.

Furthermore, the electrical bias of the substrate holder electrode at aRF voltage may be pulsed using pulsed bias signal controller (notshown). The RF power output from the RF generator may be pulsed betweenan off-state and an on-state, for example.

Alternately, RF power is applied to the substrate holder electrode atmultiple frequencies. Furthermore, impedance match network can improvethe transfer of RF power to plasma in plasma processing chamber 110 byreducing the reflected power. Match network topologies (e.g. L-type,π-type, T-type, etc.) and automatic control methods are well known tothose skilled in the art.

The upper assembly (120A, 120B, 120C) may include a gas distributionsystem (not shown). The gas distribution system may comprise ashowerhead design for introducing a mixture of process gases.Alternatively, gas distribution system may comprise a multi-zoneshowerhead design for introducing a mixture of process gases andadjusting the distribution of the mixture of process gases abovesubstrate 135. For example, the multi-zone showerhead design may beconfigured to adjust the process gas flow or composition to asubstantially peripheral region above substrate 135 relative to theamount of process gas flow or composition to a substantially centralregion above substrate 135. The gas distribution system may beintegrated with the electrode plate (126A, 126B) or antenna window 126C,for example.

A vacuum pumping system may be coupled to pumping duct 140. For example,the vacuum pumping system may include a turbo-molecular vacuum pump(TMP) capable of a pumping speed up to about 5000 liters per second (andgreater) and a gate valve for throttling the chamber pressure. Inconventional plasma processing devices utilized for dry plasma etching,a 1000 to 3000 liter per second TMP can be employed. TMPs are useful forlow pressure processing, typically less than about 50 mTorr. For highpressure processing (i.e., greater than about 100 mTorr), a mechanicalbooster pump and dry roughing pump can be used. Furthermore, a devicefor monitoring chamber pressure (not shown) can be coupled to the plasmaprocessing chamber 110.

The plasma processing chamber 110 may include a baffle plate 164configured to be coupled to an entrance to the pumping duct 140 or anannular region surrounding a peripheral edge of substrate holder 130 inplasma processing chamber 110. Due to the erosive nature of plasma,baffle plate 164 may be consumed and may require periodic replacement orrefurbishment. For example, baffle plate 164 may be a replaceableelement composed of a ferroelectric material, such as a material havinga chemical formula expressed as A_(x)(B_(y)C₁₋y)O_(z), where A, B, C aremetals and x, y, and z are positive real numbers. The ferroelectricmaterial may include barium titanate (BaTiO₃) or lead zirconate titante(PZT). Additionally, the ferroelectric material may be arranged betweentwo electrodes. Furthermore, the baffle plate 164 may include aprotective layer formed on an exterior surface arranged to be exposed toplasma. The baffle plate 164 may be removably fastened to substrateholder 130 or plasma processing chamber 110.

Any one of the replaceable chamber elements, such as focus ring 160,shield ring 162, electrode plate (126A, 126B), antenna window 126C,deposition shield 114, baffle plate 164, bellows shield 154, etc., mayinclude a protective layer, such as a coating, applied to at least aportion of an exterior surface. The coating may be composed of silicon,un-doped silicon, doped silicon, quartz, silicon carbide, siliconnitride, carbon, alumina, sapphire, ceramic, fluoropolymer, orpolyimide. Additionally, the coating may include a spray coating. Thecoating may include at least one of a Group III element (Group IIIrefers to the classical or old IUPAC notation in the Periodic Table ofElements; according to the revised or new IUPAC notation, this Groupwould refer to Group 13) and a Lanthanon element, for example. Thecoating may comprise at least one of Al₂O₃, Yttria (Y₂O₃), Sc₂O₃, Sc₂F₃,YF₃, La₂O₃, CeO₂, Eu₂O₃, and Dy₂O₃. Methods of applying spray coatingsare well known to those skilled in the art of surface materialtreatment.

As described above with reference to FIGS. 1A through 1C, plasmaprocessing system (100A, 100B, 100C) may include one or more replaceablechamber elements, such as focus ring 160, shield ring 162, electrodeplate (126A, 126B), antenna window 1260, deposition shield 114, baffleplate 164, bellows shield 154, etc. At least one replaceable chamberelement possesses a variable capacitance. The variable capacitance,replaceable chamber element is designed to include a ferroelectricmaterial. Therein, when a bias voltage is applied across theferroelectric material, the capacitance is varied.

As shown in FIG. 2, a replaceable chamber element for use in a plasmaprocessing system is illustrated. The replaceable chamber elementincludes a chamber component 200 configured to be exposed to plasma in aplasma processing system, wherein the chamber component 200 includes aferroelectric material 210 disposed between a first electrode 201 and asecond electrode 202, wherein the ferroelectric material behaves as acapacitor having a capacitance C=∈A/d, wherein ∈ is the dielectricconstant of the ferroelectric material and A is the area.

As illustrated in FIG. 3, when a bias voltage is applied across theferroelectric material between the first electrode 201 and the secondelectrode 202, the dielectric constant (∈) is varied.

Referring now to FIG. 4, a focus ring 400 and a method of fabricatingthereof are illustrated according to an embodiment. The focus ring 400is composed of a ferroelectric material, wherein a bias voltage may beapplied across the ferroelectric material between a first electrode 401and a second electrode 402. The first electrode 401 and the secondelectrode 402 may be composed of a metal-containing material or aSi-containing material, such as doped Si.

The focus ring 400 is composed of a ferroelectric material, such as amaterial having a chemical formula expressed asA_(x)(B_(y)C_(1-y))O_(z), where A, B, C are metals and x, y, and z arepositive real numbers. The ferroelectric material may include bariumtitanate (BaTiO₃) or lead zirconate titante (PZT). Furthermore, focusring 400 may include a protective layer formed on an exterior surfacearranged to be exposed to plasma.

Referring now to FIGS. 5A and 5B, a top view of a focus ring and anexploded cross-sectional view of an implementation of a variablecapacitance focus ring in a plasma processing system is depictedaccording to an embodiment. As shown in FIG. 5A, a focus ring 500includes an inner radial edge 511 and an outer radial edge 512. Focusring 500 further includes an optional step 515 located at the innerradial edge 511, wherein step 515 is configured to underlie theperipheral edge of a substrate 525.

FIG. 5B provides an exploded cross-sectional view of substrate holder520 including section A-A of focus ring 500. Substrate holder 520 mayinclude electrostatic clamp (ESC) layer 522 that includes an ESCelectrode for electrically clamping substrate 525 to substrate holder520. Additionally, substrate holder 520 may include edge insulator 530through which electrical connection to focus ring 500 may be included.

Focus ring 500 includes a ferroelectric material 501 disposed between afirst electrode 503 and a second electrode 504. Additionally, the firstelectrode 503 is configured to be coupled to a first contact electrode551 at a first voltage, and the second electrode 504 is configured to becoupled to a second contact electrode 552 at a second voltage.Furthermore, substrate holder 520 includes a voltage source 540 having afirst terminal coupled to the first contact electrode 551 and a secondterminal coupled to the second contact electrode 552, wherein a voltagedifference between the first terminal and the second terminal is used tochange the dielectric constant of ferroelectric material 501.

The voltage source 540 may include a direct current (DC) or alternatingcurrent (AC) voltage source. The voltage source 540 may include avariable DC power supply, and may include a bipolar DC power supply. Thevoltage source 540 may further include a filter 545 configured toprotect the voltage source 540 from RF power relating to plasmaformation.

Further yet, as described above, a protective layer 502 may be formed onan exterior surface of focus ring 500 arranged to be exposed to plasma.The protective layer 502 may include a Si-containing material, such asSi, SiO₂, Si₃N₄, etc. Additionally, the protective layer 502 may includedoped or un-doped Si. Furthermore, the protective layer 502 may includea spray coating. The protective layer 502, if compatible with plasma andconductive, may serve as the first electrode 503.

Referring now to FIG. 6, an electrode plate 600 and a method offabricating thereof are illustrated according to an embodiment. Whilethis embodiment is described in the context of an electrode plate, itmay also be applicable to an antenna window or a baffle plate. Theelectrode plate 600 is composed of a ferroelectric material, wherein abias voltage may be applied across the ferroelectric material between afirst electrode 601 and a second electrode 602. The first electrode 601and the second electrode 602 may be composed of a metal-containingmaterial or a Si-containing material, such as doped Si.

The electrode plate 600 is composed of a ferroelectric material, such asa material having a chemical formula expressed asA_(x)(B_(y)C_(1-y))O_(z), where A, B, C are metals and x, y, and z arepositive real numbers. The ferroelectric material may include bariumtitanate (BaTiO₃) or lead zirconate titante (PZT). Furthermore,electrode plate 600 may include a protective layer formed on an exteriorsurface arranged to be exposed to plasma.

Referring now to FIG. 7, a deposition shield 700 and a method offabricating thereof are illustrated according to an embodiment. Thedeposition shield 700 is composed of a ferroelectric material, wherein abias voltage may be applied across the ferroelectric material between afirst electrode 701 and a second electrode 702. The first electrode 701and the second electrode 702 may be composed of a metal-containingmaterial or a Si-containing material, such as doped Si.

The deposition shield 700 is composed of a ferroelectric material, suchas a material having a chemical formula expressed asA_(x)(B_(y)C_(1-y))O_(z), where A, B, C are metals and x, y, and z arepositive real numbers. The ferroelectric material may include bariumtitanate (BaTiO₃) or lead zirconate titante (PZT). Furthermore,deposition shield 700 may include a protective layer formed on anexterior surface arranged to be exposed to plasma.

Referring now to FIG. 8, a method for manufacturing a replaceablechamber element for use in a plasma processing system is describedaccording to another embodiment. The method includes flow chart 800beginning in 810 with fabricating a chamber component composed of aferroelectric material.

In 820, a first electrode is formed on a first surface of the chambercomponent.

In 830, a second electrode is formed on a second surface of the chambercomponent, wherein the ferroelectric material is disposed essentiallybetween the first electrode and the second electrode.

Furthermore, a protective layer may be formed on an exterior surface ofthe chamber component, wherein the protective layer is arranged to beexposed to plasma.

Referring now to FIG. 9, a method for performing a plasma-assistedprocess in a plasma processing system is described according to anotherembodiment. The method includes flow chart 900 beginning in 910 withdisposing a chamber component in a plasma processing system, wherein thechamber component is composed of a ferroelectric material.

In 920, a first electrode formed on the chamber component is contactedto a first contact electrode in the plasma processing system.

In 930, a second electrode formed on the chamber component is contactedto a second contact electrode in the plasma processing system.

The method may additionally include, as in 940, applying a first voltageto the first contact electrode and a second voltage to the secondcontact electrode. The method may further include, as in 950, varying avoltage difference between the first contact electrode and the secondcontact electrode to vary a capacitance of the chamber component. Forexample, a capacitance of the chamber component may be varied toincrease a lifetime of the chamber component, improve matching between afirst plasma processing chamber and a second plasma processing chamber,compensate for a drift in the plasma-assisted process from one substrateto another substrate, or reduce the seasoning time following thecleaning of the plasma processing system, or any combination of two ormore thereof.

When a voltage difference is applied across the ferroelectric materialof the chamber component (e.g., focus ring, shield ring, chamber liner,baffle plate, bellows shield, electrode plate, or antenna window), thecapacitance of the chamber component may be varied. By adjusting thecapacitance of the chamber component, at least one property of theplasma (e.g., RF current proximate the substrate) may be controlledcontinuously or non-continuously, which permits achieving a desirableplasma profile (or etch profile, deposition profile, etc.). The abilityto vary the capacitance of a chamber component allows for adjustment ofplasma properties, including plasma uniformity (or etch uniformity).

Although only certain embodiments of this invention have been describedin detail above, those skilled in the art will readily appreciate thatmany modifications are possible in the embodiments without materiallydeparting from the novel teachings and advantages of this invention.Accordingly, all such modifications are intended to be included withinthe scope of this invention.

The invention claimed is:
 1. A replaceable chamber element for use in aplasma processing system, comprising: a chamber component configured tobe exposed to plasma in a plasma processing system, said chambercomponent being fabricated of a ferroelectric material; and wherein saidchamber component includes a first electrode configured to be coupled toa first contact electrode at a first voltage, and a second electrodeconfigured to be coupled to a second contact electrode at a secondvoltage.
 2. The replaceable chamber element of claim 1, wherein saidchamber component comprises a focus ring, a shield ring, a chamberliner, a baffle plate, an electrode plate, or an antenna window.
 3. Thereplaceable chamber element of claim 1, wherein said ferroelectricmaterial includes a chemical formula expressed asA_(x)(B_(y)C_(1-y))O_(z), where A, B, C are metals and x, y, and z arepositive real numbers.
 4. The replaceable chamber element of claim 1,wherein said ferroelectric material includes barium titanate (BaTiO₃) orlead zirconate titante (PZT).
 5. The replaceable chamber element ofclaim 1, wherein said chamber component includes a protective layerformed on a surface to be exposed to plasma.
 6. The replaceable chamberelement of claim 5, wherein said protective layer contains Si.
 7. Thereplaceable chamber element of claim 5, wherein said protective layer isa spray coating containing a Group III element in the Periodic Table. 8.The replaceable chamber element of claim 1, further comprising: avoltage source having a first terminal coupled to said first contactelectrode and a second terminal coupled to said second contactelectrode, wherein a voltage difference between said first terminal andsaid second terminal is used to vary a dielectric constant of saidferroelectric material.
 9. A method for manufacturing a replaceablechamber element for use in a plasma processing system, comprising:fabricating a chamber component composed of a ferroelectric material;forming a first electrode on a first surface of said chamber component;and forming a second electrode on a second surface of said chambercomponent, said ferroelectric material is disposed essentially betweensaid first electrode and said second electrode.
 10. The method of claim9, further comprising: forming a protective layer on an exterior surfaceof said chamber component, wherein said protective layer is arranged tobe exposed to plasma.
 11. A method for performing a plasma-assistedprocess, comprising: disposing a chamber component in a plasmaprocessing system configured to generate plasma, said chamber componentbeing composed of a ferroelectric material; and forming plasma forperforming a plasma-assisted process in said plasma processing system;and varying a capacitance of said chamber component to adjust at leastone property of said plasma in said plasma processing system, said atleast one property including a plasma uniformity or an etch uniformity.12. The method of claim 11, wherein said ferroelectric material includesa chemical formula expressed as A_(x)(B_(y)C_(1-y))O_(z), where A, B, Care metals and x, y, and z are positive real numbers.
 13. The method ofclaim 11, wherein said ferroelectric material include barium titanate(BaTiO₃) or lead zirconate titante (PZT).
 14. A method for performing aplasma-assisted process, comprising: disposing a chamber component in aplasma processing system configured to generate plasma, said chambercomponent being composed of a ferroelectric material; forming plasma forperforming a plasma-assisted process in said plasma processing system;coupling a first electrode formed on said chamber component to a firstcontact electrode in said plasma processing system; coupling a secondelectrode formed on said chamber component to a second contact electrodein said plasma processing system; applying a voltage difference acrosssaid ferroelectric material between said first electrode and said secondelectrode by coupling a first voltage to said first contact electrodeand a second voltage to said second contact electrode; and varying saidvoltage difference between said first contact electrode and said secondcontact electrode to vary said capacitance of said chamber component.15. The method of claim 14, further comprising varying a capacitance ofsaid chamber component to increase a lifetime of said chamber component,improve matching between a first plasma processing chamber and a secondplasma processing chamber, compensate for a drift in saidplasma-assisted process from one substrate to another substrate, orcompensate for a drift in said plasma-assisted process from one lot ofsubstrates to another lot of substrates, or any combination of two ormore thereof.